Subject: Re: [RFC,1/2] powerpc/fsl-pci: atomic get_user when pagefault_disabled

From: Scott Wood <[email-masked]>
Date: Thu, 29 Jan 2015 23:15:01 -0600

On Tue, Nov 25, 2014 at 12:43:25PM +0100, David Hildenbrand wrote:
> Whenever we have pagefaults disabled, we have to use the atomic variants of
> (set|get)_user and copy_(from|to)_user.
> 
> Signed-off-by: David Hildenbrand <[email-masked]>
> ---
>  arch/powerpc/sysdev/fsl_pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
> index 65d2ed4..c0af4ef 100644
> --- a/arch/powerpc/sysdev/fsl_pci.c
> +++ b/arch/powerpc/sysdev/fsl_pci.c
> @@ -1025,7 +1025,7 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
>  	if (is_in_pci_mem_space(addr)) {
>  		if (user_mode(regs)) {
>  			pagefault_disable();
> -			ret = get_user(regs->nip, &inst);
> +			ret = __get_user_inatomic(regs->nip, &inst);
>  			pagefault_enable();
>  		} else {
>  			ret = probe_kernel_address(regs->nip, inst);

Please post a non-RFC version if you're ready for this to be merged.

-Scott